1. Field of the Invention
This invention relates to improvements in a mechanism for adjusting wheel alignment of a vehicle, and more particularly to a device for maintaining smaller the change in wheel alignment even upon suspension stroke.
2. Description of the Prior Art
Wheel alignment of a vehicle largely influences vehicle cruising characteristics and driveability and therefore is important from the view points of safety and riding comfort of the vehicle. Usually vehicles are so arranged that wheel alignment is to be adjustable by a mechanism even after assembly thereof. An example of such a wheel alignment adjusting mechanism is disclosed in Japanese Utility Model Provisional Publication No. 56-24371, in which a pivot pin of a suspension link can be shifted within an elongate opening formed in a member on the side of a suspension member in order to adjust toe angle, camber angle and the like.
However, drawbacks have been encountered in such a conventional wheel alignment adjusting mechanism, in which toe angle change (the change amount in wheel alignment) along with suspension stroke (bound and rebound of road wheels) becomes larger and therefore the toe angle becomes far from a design standard (represented by the character d) as seen from the characteristics represented by characters a.sub.o, a.sub.i in FIG. 7. The toe angle characteristics a.sub.o, a.sub.i in FIG. 7 are obtained by using a double wish-bone type rear suspension system in which a pivot pin for the inboard end section of a rear upper link was displaced inboard and outboard by 2 mm within the elongate opening extending in a direction from the inboard to outboard sides of a vehicle body. This means that the vehicle cruising characteristics and driveability corresponding to an initial wheel alignment cannot be maintained and unavoidably changes, thereby causing a driver to get disoriented.